android - AndEngine (Android) 中的多点触控缩放功能

Question

我正在使用 AndEngine 开发一个 Android 应用程序，我正在尝试查看是否有一个特性、功能或解决方法可以简单地通过多点触控缩放整个页面(比如当您想要在手机上放大图片)。有人可以帮忙吗。

为简单起见，假设我们想在 AndEngine 的 Lines 示例中添加多点触控缩放功能作为最简单的示例。以下是代码和截图。

package org.andengine.examples;

import java.util.Random;

import org.andengine.engine.camera.Camera;
import org.andengine.engine.options.EngineOptions;
import org.andengine.engine.options.ScreenOrientation;
import org.andengine.engine.options.resolutionpolicy.RatioResolutionPolicy;
import org.andengine.entity.primitive.Line;
import org.andengine.entity.scene.Scene;
import org.andengine.entity.util.FPSLogger;
import org.andengine.opengl.vbo.VertexBufferObjectManager;
import org.andengine.ui.activity.SimpleBaseGameActivity;

/**
 * (c) 2010 Nicolas Gramlich 
 * (c) 2011 Zynga Inc.
 * 
 * @author Nicolas Gramlich
 * @since 11:54:51 - 03.04.2010
 */
public class LineExample extends SimpleBaseGameActivity {
    // ===========================================================
    // Constants
    // ===========================================================

    /* Initializing the Random generator produces a comparable result over different versions. */
    private static final long RANDOM_SEED = 1234567890;

    private static final int CAMERA_WIDTH = 720;
    private static final int CAMERA_HEIGHT = 480;

    private static final int LINE_COUNT = 100;

    @Override
    public EngineOptions onCreateEngineOptions() {
        final Camera camera = new Camera(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT);

        return new EngineOptions(true, ScreenOrientation.LANDSCAPE_SENSOR, new RatioResolutionPolicy(CAMERA_WIDTH, CAMERA_HEIGHT), camera);
    }

    @Override
    public void onCreateResources() {

    }

    @Override
    public Scene onCreateScene() {
        this.mEngine.registerUpdateHandler(new FPSLogger());

        final Scene scene = new Scene();
        scene.getBackground().setColor(0.09804f, 0.6274f, 0.8784f);

        final Random random = new Random(RANDOM_SEED);

        final VertexBufferObjectManager vertexBufferObjectManager = this.getVertexBufferObjectManager();
        for(int i = 0; i < LINE_COUNT; i++) {
            final float x1 = random.nextFloat() * CAMERA_WIDTH;
            final float x2 = random.nextFloat() * CAMERA_WIDTH;
            final float y1 = random.nextFloat() * CAMERA_HEIGHT;
            final float y2 = random.nextFloat() * CAMERA_HEIGHT;
            final float lineWidth = random.nextFloat() * 5;

            final Line line = new Line(x1, y1, x2, y2, lineWidth, vertexBufferObjectManager);


            line.setColor(random.nextFloat(), random.nextFloat(), random.nextFloat());

            scene.attachChild(line);
        }

        return scene;
    }

}

Answer 1

可以对缩放相机应用捏合。

举个例子: http://berenoune.blogspot.com/2013/11/andengine-gles2-anchorcenter-branch.html?m=1